Pulse piston drive

ABSTRACT

A pulse piston drive having a pulse chamber with two cavities, one accommodating a piston and the other cavity being filled with an energy medium. The cavities communicate through an opening closed by a differential valve. The closing member of the valve consists of a hollow piston positioned in the cavity for the energy medium. This piston divides the cavity into portions, one of which communicates with the inner cavity of the piston and the other accommodates a drive for forcedly closing the closing member of the valve.

' [22] Filed:

United States Patent 1 1 Strizhenko et al.

1 PULSE PISTON DRIVE Oct. 29, 1971 21 Appl. No.: 193,650

[52] US. Cl 91/468, 60/261, 60/396, 251/54 [51] 1nt.' Cl. FlSb 11/08,F15b 13/042 [58'] Field of Search 91/5, 468, 432, 446; 137/509,155, 528;251/54 [56] References Cited UNITED STATES PATENTS 2,099,368 11/1937Levy ..92/134X 1 Oct. 2, 1973 2,469,038 Winkler 251/54 X 2,483,42910/1949 Pierce 188/297 X 2,633,860 4/1953 Derrington. 251/55 X 2,748,7926/1956 Davis 137/155 3,102,553 9/1963 Ottestad 137/509 3,145,056 8/1964Blahnik 251/54 X FOREIGN PATENTS OR APPLICATIONS 119,839 10/1958 U.S.S.R137/509 Primary Examinerlrwin C. Cohen Attorney-Eric H. Waters et al.

[57] ABSTRACT A pulse piston drive having a pulse chamber with twocavities, one accommodating a piston and the other cavity being filledwith an energy medium. The cavities communicate through an openingclosed by a differential valve. The closing member of the valve consistsof a hollow piston positioned in the cavity for the energy medium. Thispiston divides the cavity into portions, one of which communicates withthe inner cavity of the piston and the other accommodates a drive forforcedly closing the closing member of the valve.

1 Claim, 1 Drawing Figure ssm 1 i unsn PISTON DRIVE The presentinventionrelates to drive mechanisms and, more particularly, the invention'hasreference to pulse piston drives used in machines for pressure workingof metals.

This invention can be most effectively used in machines for cuttingingots in apparatus for continuous casting of steel and in machines forforging and stamping.

Well known in the art are piston'pulse drives comprising apulse chamberhaving 'a guide cavity for accommodation of a rod and a cavity filledwith an energy carrier periodically communicated through an openingclosed bya differential valve the closing member of which is forcedlyclosed by'a drive.

In this casethe differential closing valve comprises a closing member inthe form ofa rod located in a housing consisting of a guide sleevelocated in the pulse chamber and hermetically joined therewith throughsealing components. The drive for forcedly closing the closing'memberconsists 'of a hydraulic accumulator disposed off the pulse chamberandconnected to the closing valve through a pipeline transmitting theliquid pressure.

The most efficient pulse drives are used for creating a'liigh pressurewithin a pulse chamber. In the known pulse drives thepressure of theenergy carrier is limited due to poor reliability of the sealing devicesin the places of joining the sleeve with the bodyof the pulse chamber.To compensate for the volume occupied by the closing valve within thecavity with the energy carrier, the dimensions of the pulse chamber mustbeincrease'd. Owing to the fact that the pulse pistondrives are utilizedin machines for pulse cutting of ingots, the drives having largedimensions make it difficult to use such machines in multipass apparatusfor continuous casting of steel having a small distance between theadjacent passes. The presence ofa pipeline for transmitting'the liquidpressure from the hydraulic accumulator to the closing valve leads to anincrease in the hydraulic resistance of the flow of the liquid passingduring the opening of the "valve,thereby reducing the rate of itsopening, hence increasing the energy losses of the energy carrier whenit is passed to the under-piston space of the guide cavity.

An object of the present invention is to provide a pulse piston drivewhich allows high pressures to be created within the pulse chamber.

Another object of the invention is to provide a pulse piston'driveincreasing the efficiency of utilization of the energy during thepassage of the energy carrier into the underpiston space of the guidecavity of the pulse chamber.

These and other objects are attained due to the fact that in apulse'piston drive having a pulse chamber to accommodate a piston and acavity to be filled with an energy'carrier periodically communicatedwith the guide cavity through an opening for passing the energy carrier,according to the invention,the closing member of the valve consists of ahollow piston disposed within the space containing the energy carrierwith a gap allowing this piston to move during the passage of the energycarrier and characterized in that said piston divides the cavity filledwith the energy carrier into portions, one of which communicates withthe inner cavity of the piston through channels made in the walls ofthis piston, while the other portion accommodates a drive for forcedlyclosing the valveepiston.

Such a construction of the drive makes it possible to produce highpressures within the pulse chamber and to reduce the dimensions of thedrive.

The pulse chamber is preferably provided with a hydraulic accumulatorhaving a non-return valve with a jet, the liquid pressure of which isused for forcedly closing the valve-piston.

This provides for effective utilization of the energy.

. the-following detailed description of the invention with reference tothe accompanying drawing which shows a front sectional view of the pulsepiston drive according to the invention.

The piston pulse drive comprises a pulse chamber 1 having a guide cavity2 to accommodate a piston 3, and a cavity 4 periodically communicatedwith the cavity 2 through an opening 5. This opening is closed by adifferential valve whose closing member consists of a hollow piston 6.This piston is disposed within the cavity 4 with a gap providing for itsmovement during the passage of the energy carrier disposed within apiston 6.

The energy carrier may consist of a combustible mixture of gaseous orliquidfuel with an oxidizer or a compressed gas. 1

The piston 6 divides the cavity 4 into two portions, one of whichcommunicates with the inner cavity 7 of the piston through channels 8made in the piston walls.

filled with a liquid 11 being under pressure and providing for forcedclosing of the piston-valve. The liquid pressure is created by ahydraulic accumulator 12 mounted directly on the pulse chamber 1. Thehydraulic accumulator is equipped with a non-return valve 13 loaded witha spring 14 and having a jet 15. The valve with a jet provides forforming a considerable pass section for running the liquid intothe'hyd'raulic accumulator during the'opening of the valve-piston 6 andfor shockless closing of the valve-piston due to the throttling of theliquid through the jet 15. The hydraulic accumulator has a cavity 16filled by compressed gas to create a pressure.

The drive operates as follows.

The cavity .16 of the hydraulic accumulator 12 is filled with acompressed gas creating a required liquid pressure providing for closingthe valve-piston 6. Supplied into the passage 9 is a combustible mixturewhich into the hydraulic accumulator 12, in which case the pass sectionof the non-return valve provides for a required running speed andconsumption of the liquid at which the valve-piston 6 is opened quicklyenough.

During the movement of the valve-piston 6 there is opened thepass-through opening which provides for filling the under-piston spaceof the guide cavity 2 of the pulse chamber 1 with the energy carrierunder action of which the piston 3 acquires motion and energy necessaryfor making useful work.

After the passage of the energy carrier the pressure in the cavities 4and 7 is reduced, and the valve-piston 6 affected by the pressure of theliquid 11 closes the v opening 5. The shockless closing of thevalve-piston is provided by considerably decreasing the pass sectionwhile closing the non-return valve 13, through the jet 15 of which theliquid runs into the hydraulic accummulator. The cycle is over when thepiston 3 returns to its initial position.

We claim:

1. A pulse piston drive comprising, in combination: a pulse chamberhaving a guide cavity and a second cavity adapted to receive an energymedium, an opening communicating said guide and second cavities;reciprocable piston means being positioned in said guide cavity; adifferential valve in said second cavity adapted to periodically closesaid opening intermediate said guide and second cavities, said valveincluding a clo sure member formed as a hollow piston having an outerperipheral wall in annularly spaced relationship with the surface ofsaid second cavity so as to facilitate axial movement of said hollowpiston during flow of said energy medium, said hollow piston dividingsaid second cavity into first and second portions; annular sealing meanson said hollow piston outer peripheral wall maintaining said first andsecond portions of said second cavity in sealed relationship to eachother; channel means extending through the perhipheral wall of saidhollow piston facilitating flow of said energy medium into the firstportion of said second cavity; means for admitting said energy mediuminto said first portion of said second cavity; and hydraulicallyactuated drive means communicating with the second portion of saidsecond cavity for biasing said differential valve into closed position,said hydraulically actuated drive means comprising a hydraulicaccumulator mounted on said pulse chamber, said accumulator including aspring-biased non-return valve having a jet nozzle forming pressurizedfluid passageway means between said accumulator and the second portionof said second cavity.

1. A pulse piston drive comprising, in combination: a pulse chamberhaving a guide cavity and a second cavity adapted to receive an energymedium, an opening communicating said guide and second cavities;reciprocable piston means being positioned in said guide cavity; adifferential valve in said second cavity adapted to periodically closesaid opening intermediate said guide and second cavities, said valveincluding a closure member formed as a hollow piston having an outerperipheral wall in annularly spaced relationship with the surface ofsaid second cavity so as to facilitate axial movement of said hollowpiston during flow of said energy medium, said hollow piston dividingsaid second cavity into first and second portions; annular sealing meanson said hollow piston outer peripheral wall maintaining said first andsecond portions of said second cavity in sealed relationship to eachother; channel means extending through the perhipheral wall of saidhollow piston facilitating flow of said energy medium into the firstportion of said second cavity; means for admitting said energy mediuminto said first portion of said second cavity; and hydraulicallyactuated drive means communicating with the second portion of saidsecond cavity for biasing said differential valve into closed position,said hydraulically actuated drive means comprising a hydraulicaccumulator mounted on said pulse chamber, said accumulator including aspring-biased non-return valve having a jet nozzle forming pressurizedfluid passageway means between said accumulator and the second portionof said second cavity.